Mechanical interlock for electrical switches



April 1967 c. M. HARRINGTON ETAL 3,312,797

MECHANICAL INTERLOCK FOR ELECTRICAL SWITCHES Filed March 29, 1965 //v VEN 70/?5 RT y. Mm E 05 N 3 m mK R HWW R mw mfl .T

Mm mm CHW United States Patent 3,312,797 MECHANICAL INTERLOCK FOR ELECTRICAL SWITCHES Carl M. Harrington and Harold T. Mackensen, Columbus, Ohio, assignors to Jelfrey Galion Manufacturing Company, a corporation of Ohio Filed Mar. 29, 1965, Ser. No. 443,584 7 Claims. (Cl. 200-50) The instant invention relates to a mechanical interlock for electrical contactors.

It is the principal object of the instant invention to provide an improved mechanical interlock for electrical contactors, which is effective in response to the operation of one electrical contactor to lock another electrical contactor. This provides control of the operation of the electrical contactors, to maintain one electrical contactor in an inoperative condition during the time that another electrical contactor is energized.

It is another object of the instant invention to provide an improved mechanical interlock for electrical contactors, in which such interlock operates by a camming action, whereby upon energization of one electrical contactor, the interlock is cammed to a locking position with respect to another electrical contactor, to maintain the latter inoperative.

It is another object of the instant invention to provide a mechanical interlock for electrical contactors, in which there is an operating element connected to each contactor for operating the interlock, and there is positive engagement with the interlock to maintain one of the electrical contactors inoperative during the time that the other electrical contactor is energized.

It is still another object of the instant invention to provide an improved mechanical interlock for electrical contactors in which the interlock is of a simplified construction that is positive acting.

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims.

In the drawings:

FIG. 1 is a side elevational view of two electrical contactors mounted in adjacent disposition and including the interlock of this invention;

FIG. 2 is a bottom plan view of the electrical contactors and mechanical interlock of FIG. 1; and

FIG. 3 is a sectional view of the electrical contactors and the mechanical interlock, taken on the line 3-3 in FIG. 1.

Referring to the drawings, there is illustrated therein a pairof electrical contactors 10', which are alike in their construction in all respects. Only the electrical contactor .10 will be described hereinafter, it being understood that the description applies equally to the electrical contactor 10, in which the like parts are identified by the same reference numerals, with a prime being appended to the reference numerals. The electrical contactor, which is illustrated herein by way of example, is described in greater detail in the patent application of Carl M. Harrington, Ser. No. 307,893, filed Sept. 10, 1963, for Electrical Contactor.

The electrical contactor 10 has a frame 11 formed with a lateral leg 12 and a depending leg 13. The depending leg 13 forms the back of the contactor 10, and the latter maybe secured to a mounting panel 14 by a plurality of screws 15, 15 that are threaded into the depending leg 13. An operating coil 16 is secured to the lateral leg 12 in depending disposition. The electrical contactor 10 is operated by energization of the coil 16 which magnetizes the core 17 that extends through the center of the operating coil 16.

The electrical contactor 10 has a first terminal 20 and a second terminal 21, to each of which an electrical line may be connected in the usual manner. The contactor 10 is normally open, whereby the circuit of the electrical lines is open. Upon closing of the contactor 10, the circuit is closed, and there is provided a conducting path through the lines which are connected to the terminals 20, 21.

The first terminal 20 is connected to a first contact 22, and the second terminal 21 is connected to a second contact 23. The first contact 22 is secured in fixed position in the electrical contactor 10. The second contact 23 is mounted on the armature 24. The second contact 23 is normally spaced from the fixed contact 22 in the position of second contact 23', as seen in FIG. 1. The second contact 23 is moved into engagement with the first contact 22 by movement of the armature 24. At the lower end of the depending leg 13 there is a hollow pivot pin 25 that is laterally disposed, and on which the armature 24 is mounted for pivoting or swinging movement to bring the second contact 23 into contacting engagement with the first contact 22. Upon energization of the operating coil 16, the core 17 is magnetized and attracts the armature 24, drawing the latter upwardly, and thereby bringing the second contact 23 into contacting engagement with the first contact 22.

The electrical contactors 10, 10' are mounted in adjacent disposition, as best seen in FIGS. 2 and 3. operating element 28 is connected to the armature 24 and extends into the space between the adjacent contactors 10, 10'. The operating element 28 has a body 29, which may be formed of a suitable rigid plastic material. A supporting pin 30 has one end imbedded in the body 29 and projects laterally therefrom to be received in the bore of the hollow pivot pin 25, whereby the operating element is mounted on the contactor 10. An ear 31 extends laterallyfrom the body 29 and is engaged in a notch 32 of the armature 24. The ear 31 may be a small pin which is imbedded in the body 29 and projects laterally therefrom to engage the notch 32. Thus, the operating element 28 is pivotally mounted on the pin 25, and is connected to the armature 24, to be movable with the latter about the axis of the pin 25. The operating element 28 further includes an actuating pin 33 with one end imbedded in the body 29, and the balance of the pin 33 projects downwardly from the body 29.

An interlock supporting element 35 is disposed between the adjacent contactors 10, 10'. The supporting element 35 is formed with an upstanding leg 36, by which it is secured to the panel 14 with a suitable screw 37. The supporting element 35 has a plate 38 extending laterally from the bottom of the leg 36. The plate 38 is formed with a first track 39 and a second track 39, which have the form of slots. The actuating pins 33, 33' extend into the first and second tracks 39, 39', respectively, to be guided in their movement by the tracks 39, 39, respectively.

The mechanical interlock 40 is secured to the underside of the plate 38 on an upright pivot pin 41, whereby the interlock 40 is swingable between the contactors 10, 10. The interlock 40 has a recess 42 at one side, and a like recess 42' at the opposite side. At the forward end of the interlock 40, there is an enlarged head 43 with carn surfaces'44, 44' at the opposite sides thereof.' 7

As seen in the drawings, the electrical contactor 10 is closed, and the armature 24 has been moved upwardly by the magnetic attraction of the core 17. The operating element 28, which is connected to the armature 24, has been moved in a clockwise direction, as viewed in FIG. 1, whereby its operating pin 33 has engaged the cam surface 44 of the mechanical interlock .40. Thus, the operating element 28 has cammed the mechanical interlock 40 in a counter-clockwise direction, as viewed in FIG. 2, thereby engaging the recess 42 with the operating pin 33 of of the operating element 29'. The enlarged head 43 of the mechanical interlock 40 overlies the track 39. Thus, the interlock 40 engages the operating pin 33 in the recess 42' and also blocks movement of the pin 33'. The operating element 29' is connected to the armature 24, and the latter is thus locked and cannot be operated to close the contactor Upon opening the contactor 10, the operating pin 33 is moved rearw-ardly away from engagement with the cam surface 44. In this condition, in which neither of the contactors 10, 10 is closed, either contactor may be energized to close its respective circuit. Whichever of the contactors 10, 10' is closed, the other of the contactors is locked out by the mechanical interlock 40, in the manner above described.

The mechanical interlock, constructed in accordance with this invention, is of a simple construction and is positive acting. The positive action thereof arises by reason of the positive engagement with the mechanical interlock to actuate the latter, and further, by the positive engagement of the interlock with the locked out con-' tactor to maintain the latter in its locked out condition.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claims hereto appended, and applicants therefore wish not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of the invention, what it is desired to secure by Letters Patent of the United States is:

1. A first electrical contactor and a second electrical contactor arranged in adjacent disposition on a mounting structure, said first and second contactors each including a first contact and a second movable contact that are normally spaced from each other, said first contactor including a first movable armature for said movable contact that is movable from an open position to a closed position to bring the movable contact into abutment with said first contact to close a circuit, said second contactor including a second movable armature for said movable contact that is movable from an open position to a closed position to bring the movable contact into abutment with said first contact to close a circuit, an interlock for said first and second contactors, a first operator element connected to said first armature, a second operator element connected to said second armature, said interlock including a first recess to engage said first operator element and a second recess to engage said second operator element, each of said operator elements being disposed adjacent said interlock and upon movement of one armature to closed position the respective operator element being moved thereby to engage the interlock and to move the interlock towards the other operator element to engage the respective recess of the interlock with the other operator element to lock the other armature in open position, said interlock being swingable between said first operator element and said second operator element, and pivot means to swingably support said interlock.

2. A first elect-rical contactor and a second electrical contactor arranged in adjacent disposition on a mounting structure, said first and second contactors each including a first contact and a second movable contact that are normally spaced from each other, said first contactor including a first movable armature for said movable contact that is movable from an open position to a closed position to bring the movable contact into abutment with said first contact to close a circuit, said second contactor including a second movable armature for said movable contact that is movable from an open position to a closed position to bring the movable contact into abutment with said first contact to close a circuit, an interlock for said first and second contactors, a first operator element connected to said first armature, a second operator element connected to said second armature, said interlock including a first recess to engage said first operator element and a second recess to engage said second operator element, each of said operator elements being disposed adjacent said interlock and upon movement of one armature to closed position the respective operator element being moved thereby to engage the interlock and to move the interlock towards the other operator element to engage the respective recess of the interlock with the other operator element to lock the other armature in open position, said interlock including cam means to be engaged by one of said first operator element and said second operator element, and engagement of one operator element with said interlock cam means moving the interlock towards the other operator element to engage the respective one of said interlock recesses with said other operator.

3. A first electrical contactor and a second electrical contactor arranged in adjacent disposition on a mounting structure, said first and second contactors each including a first contact and a second movable contact that are normally spaced from each other, said first contactor including a first movable armature for said movable contact that is movable from an open position to a closed position to bring the movable contact into abutment with said first contact to close a circuit, said second contactor including a second movable armature for said movable contact that is movable from an open position to a closed position to bring the movable contact into abutment with said first contact to close a circuit, an interlock for said first and second contactors, a first operator element connectedto said first armature, a second operator element connected to said second armature, said interlock including a first recess to engage said first operator element and a second recess to engage said second operator element, each of said operator elements being disposed adjacent said interlock and upon movement of one armature to closed position the respective operator element being moved thereby to engage the interlock and to move-the interlock towards the other operator element to engage the respective. recess of the interlock with the other operator element to lock the other armature in open position, a support for said interlock, said support having a first track for said first operator element and a second track for said second operator element for guiding the movement of the first and second operator elements, respectively, and said interlock being mounted on said support between said first and second tracks. 7

4. A first electrical contactor and a second electrical contactor as recited in claim 3 in which said first track and said second track each comprises a slot in said support, and said first operator element and said second operator element each comprises an actuating pin extending through the respective slot to adjacent said inter- :lock.

5. A first electrical contactor and a second electrical contactor as recited in claim 4 in which the interlock has an enlarged head to overlie one of said first track slot and said second track slot, said enlarged head having a first cam surface adjacent said first operator element and a second cam surface adjacent said second operator element, one of said first operator element and said second operator element engaging the respective one of said first cam surface and said second cam suface to move the interlock head to overlie the respective one of said first track slot and said second track slot and to secure the other operator element in the respective one of said first interlock recess and said second interlock recess.

6. A first electrical contactor and a second electrical contactor arranged in adjacent disposition on a mounting structure, said first and second contactors each including a first contact and a second movable contact that are normally spaced from each other, said first contactor including a first movable armature for said movable contact that is movable from an open position to a closed position to bring the movable contact into abutment With said first contact to close a circuit, said second contactor including a second movable armature for said movable contact that is movable from an open position to a closed positionto bring the movable contact into abutment with said first contact to close a circuit, an interlock for said first and second contactors, a first operator element connected to said first armature, a second operator element connected to said second armature, said interlock including a first recess to engage said first operator element and a second recess to engage said second operator element, each of said operator elements being disposed adjacent said interlock and upon movement of one armature to closed position the respective operator'element being moved thereby to engage the interlock and to move the interlock towards the other operator element to engage the respective recess of the interlock with the other operator element to lock the other armature in open position, said first armature being mounted on a first pin and said secondarmature being mounted on a second pin for pivotal movement thereof, and said first operator element being supported on said first pin of said first armature and said second operator element being supported on said second pin of said second armature.

7. A first electrical contactor and a second electrical contactor arranged in adjacent disposition on a mounting structure, said first and second cont-actors each including a first contact and a second movable contact that are normally spaced from each other, said first contactor including a first movable armature for said movable contact that is movable from an open position to a closed position to bring the movable contact into abutment with said first contact to close a circuit, said second contactor including a second movable armature for said movable contact that is movable from an open position to a closed position to bring the movable contact into abutment with said first contact to close a circuit, an interlock for said first and second contactors, a first operator element connected to said first armature, a second operator element connected to said second armature, said interlock including a first recess to engage said first operator element and a second recess to engage said second operator element, each of said operator elements being disposed adjacent said interlock and upon movement of one armature to closed position the respective operator element being moved thereby to engage the interlock and to move the interlock towards the other operator element to engage the respective recess of the interlock with the other operator element to lock the other armature in open position, said first armature being mounted on a hollow pin and said second armature being mounted on a hollow pin for pivotal movement thereof, said first operator element having a pin extending into said hollow pin of said first armature and said second operator element having a pin extending into said hollow pin of said second armature to support the first and second operator elements, respectively, said first operator element being connected to said first armature by an ear engaged in a notch and said second operator element being connected to said second armature by an ear engaged in a notch for movement of each operating element by the respective armature.

ROBERT K. SCI-IAEFER, Primary Examiner. I. R. SCOTT, Assistant Examiner. 

1. A FIRST ELECTRICAL CONTACTOR AND A SECOND ELECTRICAL CONTACTOR ARRANGED IN ADJACENT DISPOSITION ON A MOUNTING STRUCTURE, SAID FIRST AND SECOND CONTACTORS EACH INCLUDING A FIRST CONTACT AND A SECOND MOVABLE CONTACT THAT ARE NORMALLY SPACED FROM EACH OTHER, SAID FIRST CONTACTOR INCLUDING A FIRST MOVABLE ARMATURE FOR SAID MOVABLE CONTACT THAT IS MOVABLE FROM AN OPEN POSITION TO A CLOSED POSITION TO BRING THE MOVABLE CONTACT INTO ABUTMENT WITH SAID FIRST CONTACT TO CLOSE A CIRCUIT, SAID SECOND CONTACTOR INCLUDING A SECOND MOVABLE ARMATURE FOR SAID MOVABLE CONTACT THAT IS MOVABLE FROM AN OPEN POSITION TO A CLOSED POSITION TO BRING THE MOVABLE CONTACT INTO ABUTMENT WITH SAID FIRST CONTACT TO CLOSE A CIRCUIT, AN INTERLOCK FOR SAID FIRST AND SECOND CONTRACTORS, A FIRST OPERATOR ELEMENT CONNECTED TO SAID FIRST ARMATURE, A SECOND OPERATOR ELEMENT CONNECTED TO SAID SECOND ARMATURE, SAID INTERLOCK INCLUDING A FIRST RECESS TO ENGATE SAID FIRST OPERATOR ELEMENT AND A SECOND RECESS TO ENGAGE SAID SECOND OPERATOR ELEMENT, EACH OF SAID OPERATOR ELEMENTS BEING DISPOSED ADJACENT SAID INTERLOCK AND UPON MOVEMENT OF ONE ARMATURE TO CLOSED POSITION THE RESPECTIVE OPERATOR ELEMENT BEING MOVEED THEREBY TO ENGAGE THE INTERLOCK AND TO MOVE THE INTERLOCK TOWARDS THE OTHER OPERATOR ELEMENT TO ENGAGE THE RESPECTIVE RECESS OF THE INTERLOCK WITH THE OTHER OPERATOR ELEMENT TO LOCK THE OTHER ARMATURE IN OPEN POSITION, SAID INTERLOCK BEING SWINGABLE BETWEEN SAID FIRST OPERATOR ELEMENT AND SAID SECOND OPERATOR ELEMENT, AND PIVOT MEANS TO SWINGABLY SUPPORT SAID INTERLOCK. 